21436900 has 27 divisors (see below), whose sum is σ = 46618761. Its totient is φ = 8556240.

The previous prime is 21436873. The next prime is 21436927. The reversal of 21436900 is 963412.

The square root of 21436900 is 4630.

It is a perfect power (a square), and thus also a powerful number.

It is an interprime number because it is at equal distance from previous prime (21436873) and next prime (21436927).

It can be written as a sum of positive squares in only one way, i.e., 7717284 + 13719616 = 2778^2 + 3704^2 .

It is a super-2 number, since 2×21436900² = 919081363220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 46069 + ... + 46531.

Almost surely, 2^21436900 is an apocalyptic number.

21436900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21436900 is the 4630-th square number.

It is an amenable number.

21436900 is an abundant number, since it is smaller than the sum of its proper divisors (25181861).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21436900 is an equidigital number, since it uses as much as digits as its factorization.

21436900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 940 (or 470 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The cubic root of 21436900 is about 277.7925923951.

Multiplying 21436900 by its sum of digits (25), we get a square (535922500 = 23150²).

21436900 divided by its sum of digits (25) gives a square (857476 = 926²).

Multiplying 21436900 by its product of nonzero digits (1296), we get a square (27782222400 = 166680²).

It can be divided in two parts, 21 and 436900, that added together give a square (436921 = 661²).

The spelling of 21436900 in words is "twenty-one million, four hundred thirty-six thousand, nine hundred".